Jenson Button cruised to an imperious Belgian Grand Prix win after he escaped a first-corner multi-car accident triggered by Romain Grosjean that later result in the Lotus driver receiving a one-race ban and a €50,000 fine.

Button was followed to the podium by Sebastian Vettel and Kimi Raikkonen but the race could have had an entirely different complexion had Grosjean not collided with Lewis Hamilton at the start, an incident that sparked a multi-car pile in which the French driver’s car was sent flying into back of Sergio Pérez’s Sauber and then across the nose of Fernando Alonso’s Ferrari. All four were dumped out of the race.

Hamilton confronted Grosjean in the gravel trap but after being led away the Briton refused to comment in the incident, saying he wished to simply “move on”. Fernando Alonso meanwhile, emerged dazed from his Ferrari and was helped away from the by circuit medical officials. He later reported that he had stayed in the car briefly as he had experienced a small amount of back pain.

“I stayed in the car for a few seconds because I had back pain,” he said. “Then there was a little bit of fire so they came with extinguishers and I decided to jump out because I could not breathe with all the smoke there.

“I'm lucky that I can be in the car in five days at Monza because looking at the image, we were turning in so you could have a problem with your hands or even your head because [Grosjean's] car was so close,” he said. “I think we broke everything on top of the car. It was lucky in that aspect.”

The accident delivered a double blow to Sauber. Kamui Kobayashi, starting from second had looked ideally placed to score his first podium finish but the Japanese driver was also caught up in the chaos at La Source. He retreated to the pits for repair and retook the course but dropped to the back of the field could find now way back into the race and finished 13th.

The pile-up was immediately placed under investigation by the stewards and after the race they delivered their verdict: a one-race suspension and a €50,000 fine.

An FIA statement on the incident read: “The stewards regard this incident as an extremely serious breach of the regulations which had the potential to cause injury to others. It eliminated leading championship contenders from the race.”

When the debris had been cleared and the race resumed, Button simply strode away from his rivals. Behind him more action unfolded as Nico Hulkenberg briefly jumped into podium contention and Sebastian Vettel put in a superb drive to reach second from a 10th-place start but for Button it would have been white noise, a dull thrum that barely broached the serenity of his progress to his 14th career win.

“To lead from start to finish, it’s a very special victory,” he said. “But I think you’re going to say that about every victory. But it’s really nice to win on a circuit like this. I remember watching Formula One back in the day here – it was a little bit different then – and there’s so much history. It’s really good to be a part of that.”

Button admitted, however, that the one-stop strategy that gave him the comfort zone he needed hadn’t been an automatic choice.

“We weren’t really sure what to do with the strategy: whether it was going to be a one or a two, and we thought some people might even be doing a three and really we were just playing it by ear,” he said. “When Nico [Hülkenberg] got into second it did help us a little bit because I could just feel the car and not push it too hard and at that point I still didn’t think we were going to do a one-stop, I still thought it was going to be a two. And then on lap 12 the tyres started working and the car felt very consistent, really good to drive and I could control the degradation of the tyres. It’s always easier when you’re leading a race, to do that.”

Vettel’s climb to the second step of the programme was somewhat more harum scarum. When the start lights went out the Red Bull Racing driver got away badly, slipping back to 12th and into the hail of debris raining down on the track from the accident at the front. Vettel negotiated his way through the chaos and then set about finding a way back into points contention.

Ultimately, that was achieved by gambling on a one-stop strategy when most around him, save Button, opted for a two-stop race. Finding his starting medium tyre more durable than expected Red Bull Racing opted to keep the German out and he soon climbed from the midfield to third by lap 15. That put him behind Michael Schumacher, who at the time was also pursuing a one-stop race.

By lap 19, Vettel had chased his compatriot down and was harrying him on the run up to the Bus Stop chicane. Schumacher took a wide line into the first part and Vettel tucked inside looking for a gap. Suddenly Schumacher cut across the Red Bull driver and dived into pit lane, forcing Vettel to take wildly evasive action.

Afterwards, though, Vettel refused to lay blame for the incident at the feet of the Mercedes driver. “With Michael I think there was bit of confusion,” he said. “Probably he wasn’t keen to defend his position because he was going tot pits anyway but I thought he would block the inside and then he came on the outside. It was very close under braking. I nearly ran into the back of his car. I tried to get into a better position for the start-finish straight but he kept turning right and went into the pits. I was twice very lucky not to lose my front wing. But I think it was just a bit of confusion.”

Vettel himself pitted on the lap after the incident and, as Button ahead, had a largely comfortable run to the flag. Like Button, he admitted the one-stop strategy was a response to the race conditions.

“I had a very poor initial launch and lost positions,” he said. “ But we were able to get through the field though it’s not that easy when everyone has DRS available: it’s like a big chain and you sit on the limiter like everyone else. It’s difficult to benefit from that but I think we made reasonable progress through the field. And then we were able to have a couple of good laps in clean air, which I think was the right way.

“That obviously allowed us to come back through the strategy and finish second, which I think after the first lap nobody expected. We didn’t expect the tyres to last that well, I think there was some talk before the race, there were some concerns the tyres wouldn’t last that long. Probably most people were thinking of two and three stops and one stop seemed out of reach. Same for us but after a couple of laps it was clear that the tyres were lasting pretty well and the pace wasn’t bad – that was the most important thing for us.”

Raikkonen meanwhile was having his own struggles. Starting third, the Finn see-sawed his way in and out of the podium positions all afternoon, before finally slotting into third on lap 31. Once there, he tried to make an impression on the 13-second gap to Vettel ahead but it soon became clear that Vettel was pacing himself and Raikkonen settled for third third-place finish of the season and his sixth podium of the year.

“My car wasn’t very nice to drive the whole race,” he said. “Even yesterday, with new tyres in qualifying, it was OK but we were quite far away from the guys in front of us, so I wasn’t expecting a very easy ride and it turned out to be very difficult.

“I had no grip,” he added. “ The first few laps with new tyres were always good but then sliding: no front end, no rear end, just struggling with the grip and so we had to run a bit more downforce to get grip and we were really slow in a straight line. But we had a third place so it’s OK. Not the easiest race but pretty OK.”

Behind the Lotus driver, Nico Hulkenberg, who had raced in second behind Button for much of the opening phase of the race eventually finished fourth having started 11th and Felipe Massa scored his best result since the British Grand Prix with a fifth-place finish.

Massa’s solid performance won’t have pleased Mark Webber. The Aussie had predicted a tough afternoon after qualifying seventh and then being forced to start 12th after his RB8 required an unscheduled gearbox change. But with championship rival Alonso removed from the race equation at the start, the afternoon suddenly looked a lot brighter and Webber began a slow climb up the field. He rose as high as fourth by the race’s mid-point but was later eclipsed by one-stopping team-mate Vettel and also by Massa.

“The start was pretty wild which can happen here at La Source. Then we settled into a race where it rapidly became clear that it was very difficult for us to overtake on track. After Eau Rouge it was just not possible for us to fight with people on the straight after that. That made it tough. We tried to undercut some people and after that you just roll the dice. The stars just didn’t line up too much after the first lap really. I had a bit of luck there but after that pretty much not. We got some good points, but it would have been nice to get a few more.”

Webber was placed under investigation during the race for a suspect unsafe release in his second pit stop but in the immediate aftermath of the race he was confident he would escape sanction.

“It was OK,” he said. “I knew I had Felipe there. I rolled out a little bit, let him merge in and then moved out and took the fast lane. No problem.”

And so it proved, with the stewards ruling that Webber had indeed delayed his exit to allow Massa to reach his pit box.

The result means Vettel climbs above his team-mate into second position in the Drivers’ Championship with 140 points, just 24 behind the non-finishing Alonso. Webber, meanwhile, sits third with 132 points, now just a single point ahead of Raikkonen. Lewis Hamilton is fifth on 117 points and Button’s win, his first since the opening round in Australia, mean he now has 101 points.